The present invention relates to a method for preparing an anode active material of a lithium secondary battery and an anode active material prepared by the same, and more particularly, to a method for preparing an anode active material based on carbide-derived carbon having pores therein and an anode active material prepared by the same.
Generally, carbon is classified into amorphous carbon, graphite, diamond, fullerene-like structures, nanotubes, and the like depending on properties thereof, and carbon having specific structures and properties can be created by varying reaction conditions. Graphite requires high temperature conditions and carbon atoms of graphite exhibit extremely low mobility. Diamond requires difficult reaction conditions based on high pressure or high-energy activation technology. Recently, with the development of nano-techniques, demand for techniques capable of controlling growth of atomic-level carbon materials has been increasing.
Carbon is mainly used as an anode material for secondary batteries, particularly, lithium secondary batteries. More particularly, hard carbon, which is non-graphite carbon, or graphitized soft carbon is mainly used as the anode material.
Graphite constituting a LiC6 structure has a theoretical capacity of 380 mAh/g based on a charge-discharge reaction mechanism of secondary batteries, and carbonized materials having a structure beyond such theoretical capacity based on the charge-discharge reaction mechanism have been developed in the art.
Carbide-derived carbon (CDC) is a carbon material prepared by selectively removing metal atoms from crystalline metal carbide, which is a compound of metal and carbon and has a highly crystalline structure, and nano-sized pores are formed at positions from which metal atoms are removed (Korean Patent Application Publication No. 10-2001-0013225 A).
The carbide-derived carbon allows efficient supply and discharge of reactants and by-products through the nano-sized pores, and has a large surface area. Therefore, efforts to use the carbide-derived carbon as an energy reservoir are ongoing, and although technology to apply the carbide-derived carbon to an anode material for secondary batteries has been developed (Korean Patent No. 10-0814817), the technology in the art has insufficient efficiency.
The present invention solves these problems, as well as others.